Forza Horizon 5

Once you have completed the first showcase event, it being the "On a Wing and a Prayer Showcase", you will unlock several Horizon Race events to start with as more unlock later. Simply set a marker to one of the events on the map and complete it, you do not need to win, and will get the achievement. Your earliest options will be the Horizon Mexico Circuit which is located in the first Forza Horizon festival area, the Desierto Trail slightly to the east of the main festival area, Oasis Cross Country which is located right below the Desierto Trail, the Mulege Town Scramble to the south of the main festival in the town of Mulege, the Airfield Cross Country Circuit to the south of the town Mulege, and lastly the Emerald Circuit to the West of the main festival area past Costa Rocosa. Choose any one of the events and race to 10 G!